(a) Field of the Invention
This invention relates to a device for lifting dies and more particularly, but not by way of limitation to a lift mechanism used in a filler block of a press brake for removing and installing press brake dies.
(b) Description of the Prior Art
Heretofore, there have been a variety of adjustable die holders and compensating brake die holders having a plurality of adjustable wedges for providing vertical adjustment and compensating camber to die holders. These type of adjustable wedges are described, for example in Bath U.S. Pat. No. 2,456,856; Fritsch; U.S. Pat. No. 3,587,286; Roch U.S. Pat. No. 3,965,721; Deguchi U.S. Pat. No. 4,354,374; and Russell U.S. Pat. No. 4,736,612. None of these above-mentioned patents disclose a lift mechanism for easily removing and installing press brake dies.
In Murphy U.S. Pat. Nos. 4,691,554 and 4,700,624; Fleischer, et al. U.S. Pat. No. 4,819,554; and Fisch U.S. Pat. No. 4,669,297, a number of different types of die transfer systems are described for use with punch presses and injection molding fixtures having a bolster plate with a conventional inverted T-slot. The T-slots are used both to contain a lift device and to pull a tooling fixture surface against the bolster plate. The lift device is compressed by variously using bellville springs, elastomeric coils and air bags. None of these patents describe the unique combination and structure described herein as used with a filler block in a conventional press brake operation.